Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Stanford researchers study how gene level variations in blood affect immunity

13.02.2003


Differences in people seem to run in the blood, according to a recent study that examines which genes are active in blood cells. The work, published in this week’s online issue of the Proceedings of the National Academy of Sciences, found that the levels of several genes used by blood cells vary from person to person.



"Nobody had taken this broad a look at genetic variation in the blood of healthy people," said David Relman, MD, associate professor of medicine at Stanford and a co-author of the study.

People vary greatly in their reactions to bacteria and viruses; some individuals fall prey to every bug that comes along while others go through winter sniffle-free. Relman, along with Patrick Brown, PhD, professor of biochemistry, and research assistant Adeline Whitney thought these differences might show up when looking at which genes are active in circulating blood cells.


To find out the extent and nature of the differences in gene activity in people’s blood, Relman and his colleagues drew blood from 75 healthy people and extracted a molecule called RNA. RNA is produced by active genes and can be used to identify which genes are being expressed in a given sample. They then attached a fluorescent molecule to the RNA and applied the samples to a gene chip - a glass slide dotted with human genes. If a sample contained RNA corresponding to a gene on the chip, the fluorescently labeled RNA would bind to the spot and produce a visible signal. The bigger the signal, the more RNA was present, and therefore the greater the gene expression. Whitney then compared which spots varied in brightness among the samples.

The blood used in this analysis contained a variety of cells, including red blood cells that carry oxygen to the tissues and immune cells that fight disease. The red blood cells don’t contain nuclei and therefore don’t produce RNA. That leaves immune cells as the only cells making RNA in the blood sample. Any differences found in the pattern of active genes resulted from these disease-fighting cells.

A few genes stood out as being used at varying levels in different people. Some of these could be used to distinguish between men and women. For example, women use different levels of genes whose proteins respond to an immune protein called interferon. Researchers had suspected that genes in the interferon pathway might have a role in the higher risk of autoimmune diseases among women.

The researchers also found variations in two genes that weren’t previously documented as being active in blood cells. One is a gene that makes the prion protein - the protein altered in people who have Creutzfeldt-Jakob disease. Another surprisingly variable gene was BRCA1, which is mutated in an inherited form of breast cancer. It could turn out that levels of the prion protein or BRCA1 in the blood play some role in determining the risk for prion-related diseases or cancer.

In addition to the variation of gene expression among different people, the researchers found genes that varied according to the time of day that blood was drawn. Other genes were used at higher or lower levels depending upon the age of the blood donor - a finding that could eventually help doctors understand why older people are more prone to some illnesses.

Relman pointed out that it’s too early to know why people use genes at higher or lower levels in blood cells, and the consequences of this variability. "It may be that some people confronted a virus or had a cold the week before, or had different environmental experiences," he said.

He added that despite the differences, there was remarkable similarity in the genes used in the blood cells among the study subjects. "It was surprising that the degree of variability was as small as it turns out to be," he said. This finding bodes well for using gene expression in blood to distinguish between healthy people and those with an infectious disease. Because people are usually quite similar, any disease-related variation should stand out.


Other Stanford researchers who contributed to the paper include MD/PhD students Maximillian Diehn, PhD, and Ash Alizadeh, PhD; postdoctoral fellow Stephen Popper, DSc; and medical student Jennifer Boldrick.

Stanford University Medical Center integrates research, medical education and patient care at its three institutions - Stanford University School of Medicine, Stanford Hospital & Clinics and Lucile Packard Children’s Hospital at Stanford. For more information, please visit the Web site of the medical center’s Office of Communication & Public Affairs at http://mednews.stanford.edu.

PRINT MEDIA CONTACTS: Amy Adams at (650) 723-3900 (amyadams@stanford.edu)
BROADCAST MEDIA CONTACT: Neale Mulligan at (650) 724-2454 (nealem@stanford.edu)

Neale Mulligan | EurekAlert!
Further information:
http://med-www.stanford.edu/MedCenter/MedSchool/

More articles from Health and Medicine:

nachricht Research reveals how diabetes in pregnancy affects baby's heart
13.12.2017 | University of California - Los Angeles Health Sciences

nachricht Routing gene therapy directly into the brain
07.12.2017 | Boston Children's Hospital

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Gecko adhesion technology moves closer to industrial uses

13.12.2017 | Information Technology

Columbia engineers create artificial graphene in a nanofabricated semiconductor structure

13.12.2017 | Physics and Astronomy

Research reveals how diabetes in pregnancy affects baby's heart

13.12.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>